There's no such thing as a "Linux professional", so no.
Linux from scratch is a book describing how to create and build your own Linux distribution from nothing, building every package from source and installing it.
Yes. All you have to do is give Linux its own partition.
No. Apple uses their own operating system. Linux is used by the cool people
Linux Wine is an open source software program. The Linux Wine software program allows Linux users to run Windows programs on their own devices such as computers.
You have to draw your own conclusions about Linux, based on your own observations. Some people love it, some people hate it, and most have never heard of it or used it.
Linux cannot be learned from reading a book. It can only be learned by hands-on experience. If you really want to get into the guts of Linux, get the Linux From Scratch manual. This manual will instruct you in building your own Linux distro from the ground up.
Some different operating systems such as different versions of Linux may be downloaded for free through Ubuntu, Cnet or Linux. Other systems such as those for Microsoft or Apple must be purchased and then downloaded via the vendors own portal.
Yes, it is possible for you to rekey your own locks with the right tools and knowledge. However, it can be a complex process and may be best left to a professional locksmith to ensure it is done correctly.
Everything.* * Subject to your own understanding and skills.
do your own research
There are Windows Server, Linux, BSD, and even Apple's own server
Heavens no! Microsoft is actually a pretty vocal opponent to Linux adoption, as it seriously threatens their market share. The Linux trademark is own by its creator, Linus Torvalds, and the Linux kernel itself is under dozens, if not hundreds, of copyrights to hundreds of holders.